Our expert advice in this Sleeping Bag Gear Guide should help you answer that important question and ensure you get a good nights rest.
Sleeping bags vary a lot in price; you should know beforehand what to look for when buying one. In this section we aim to give you the information you need to buy the right sleeping bag, as buying the wrong one could lead to a long, cold, miserable night.
The main areas to look at is, firstly, a sleeping bag that will keep your body warm enough for the weather conditions you are likely to use it in, secondly, its bulkiness. And there lies the problem, the warmer your bag is, the more insulation material it contains and therefore the bulkier and heavier it will be. It is important therefore to consider the temperature range you will need your bag for and then to consider the options and materials available to you.
Comfort Temperature Ratings
Manufacturers do tend to give their sleeping bags a ‘comfort temperature rating’ – these indicate the lowest temperature that an average person will be able to get a good nights sleep at, however there are factors that affect an individuals comfort rating, such as age, gender, health, metabolism, environmental conditions such as wind-chill and humidity, as well as the protection offered by your tent and ratings do assume that you use a sleeping mat. Ratings are often expressed in different ways according to manufacturer, for example some will give a 3 or 4 season rating, others give maximum, minimum and comfort temperatures, with the bag being comfortable half way between the stated extremes. Manufacturers also us e different methods to rate their bags, a new test EN13537 has recently been introduced making it easy to compare bags tested this way, however how accurate it is is still under debate. So this comfort temperature rating can give you an indication but cannot be taken as absolute and tread carefully when comparing bags.
As a general rule, if you think you feel the cold more than the average person then go for a bag which has a comfort rating 5ºC colder than the conditions will be.
For example, if you expect –10ºC then buy a –15ºC bag.
Insulation Materials: Down Versus Synthetic
Natural down clusters and synthetic wadding are the two main types of air-trapping insulation material used to make sleeping bags.
|DOWN ||SYNTHETIC |
- Warmth to weight ratio is far greater than any synthetic.
- Small pack size.
- Greater breathability.
- Will cover wider range of temperatures.
- Will last years longer if looked after.
- Relatively inexpensive.
- Dries and cleans easily.
- Retains up to 70% performance when wet.
- Can be stored compressed (not for long periods.)
|CON's ||CON's |
- More expensive.
- Useless when wet.
- Difficult to wash and dry.
- Shouldn’t be stored compressed.
- Heavier weight.
- Covers less range of temperature.
- Shorter life span than down.
- Larger pack size
Down is the most efficient and long lasting the sleeping bags are smaller and lighter and feel much softer, however they do lose their insulating qualities when wet, are difficult to clean and more expensive. Down sleeping bags do offer the best warmth to weight ratio, if you need a very warm bag
(-15ºC or lower?) then buy down. Fillpower and construction also needs to be considered when buying a down bag. Fill weight tells you how much down is in the bag, however the better the down in terms of fillpower the less you need to keep warm. Fillpower gives a gauge of how efficient the down is at trapping air – e.g. a 30g sample of down with a fillpower of 600+ will occupy a minimum of 600 cubic inches. Therefore, the higher the fillpower, the better the performance of the bag.
Note : American companies calculate fillpower in a different way from the European method, resulting in slightly higher figures (500 European = approx 550 American). When you see a bags down/feather ratio it means the following: - 90/10 would mean 90% down and 10% feather. You may ask ‘why isn’t it 100% down’, the answer is that the down requires a certain amount of feather so it has something to cling to – like leaves on a branch. Any less than 3% feathers and the down will have no purchase and will just clump together and not loft. Any more than 10-12% feather and there will not be enough down and the performance will be adversely affected. Construction methods affect the down distribution and therefore insulation, methods such as V-baffle and shingle construction offer good down distribution and resistance to shift, but are more expensive. Stitch through and box wall construction is cheaper but will allow cold spots.
Synthetic Sleeping Bags
Synthetic sleeping bags are far cheaper. Synthetic insulation performs better than down when wet but they are bulkier and heavier. Buy synthetic if you are on a budget or intend to use the bag in damp conditions regularly or will want to wash it regularly. The same rules for construction apply to synthetic bags, if stitched through cold spots can form, look for bags with a shingle construction.
Other features to consider :
Hood : test the hood, pull it tight and see whether it feels comfortable and whether it restricts your vision, see how easy it is to tighten and slacken.
Shoulder baffle : A shoulder or neck baffle helps to trap warm air inside the bag, check that your selected bag has one and if it is comfortable and easy to tighten.
Side Zips : Two way zips running the whole length enable you to let your feet cool down and extra movement, check the zip a few times to ensure it does not snag.
Materials : Nylon is the standard fabric for both lining and shell as it is breathable, quick drying and durable. Polycotton is often used for lining but is slow during and adds weight and bulk. Pertex is often used on the pricier bags, as it is lightweight and very breathable.